Treating lubricating oils



Aug 6, 1935.

E. AYRES EIAL TREATING LUBRICATING OILS HALOGENATE H YOROFARB Pkssaunr: OPT/OM41.)

Filed Aug. 11, 1952 AL GL AGITATOR H6! TATOR IF'IEE AND STEM 57']!- oer/pun.

TREHTE D LUBRICAHNG FRACTIONATOR OIL 011001.: usnr RESIDUE FRACTION FRACTION FIN/SHED OFHONAL LUBRIcAT'Ins OIL FINISH/N6 STEPS 3mm 15 enefl res mrsc figz, (asain,

Patented Aug. 6, 1935 2,010,387

UNlT-ED STATES PATENT OFFICE TREATING LUBRICATING OILS Eugene Ayres and Herschel G. Smith, Swarthmore, Pa., assignors to Gulf Refining Company, Pittsburgh, Pa., a corporation of Texas Application August, 11, 1932, Serial No. 628,446

12 Claims. (Cl. 196-78) This invention relates to treating lubricating cating oils with halogenated hydrocarbons in the oils; and it comprises a process wherein a lubripresence of aluminum chloride and at moderate eating oil stock is mixed with a small percentage temperatures, a remarkable and specific alteraof aluminum chloride and with a halogenated tion of their properties is effected. -The charhydrocarbon, such as an alkyl, aralkyl, ,alkylene acteristicsof such stocks are changed .in various 5 or aryl halide, usually containing not more than ways, depending to some extent upon the nature one halogen atom attached to any one carbon of the chlorinated hydrocarbon used and upon atom, the mixture is heated at moderate temthe conditions of treatment. In general, treatperatures and the resulting sour oil is sweetened ment with halogenated hydrocarbons having not i and purified; all as more fully hereinafter set more than a single halogen atom attached to forth and as claimed. any one carbon atom increases the A. P. I. grav- Within the past few years there has arisen an ity, lowers the carbon residue and raises the visimportant demand for lubricating oils of diverse cosity as well as the viscosity index. By this but specific properties. The usual procedure emmethod, for example, coastal lubricating oils havplayed to obtain oils with specific properties has ing low gravity, viscosity and viscosity index can been to derive such oils from an appropriate beso far improved that their properties approach crude petroleum, because each crude is capable those of the best grade paraflin type, mid-conof yielding oils of certain characteristic propertinent oils. Butby selection of the particular ties. It has not always been possible, however, hydrocarbon halide used in the process, it is pos- I to obtain certain extreme combinations of prop- 'sible to change the properties of an oil almost erties by the ordinary refining methods, and it at will. has not always been practicable to depend upon In our process the oil to be treated is mixed the availability of a suflicient variety of crudes with a substantial amount, say 5 to per cent to satisfy market demands. Various methods by weight, of chlorinated hydrocarbon, such as have been proposed for the modification of the an alkyl, alkylene, or-aryl monoor poly-halide, properties of lubricating oils to'simulate in cera small amount of aluminum chloride (usually tain respects the properties of lubricating oils from 1 to 10 per cent) is added and the r l m from other types of crude, but all such methods .m tu e is heated under agitating conditions to have been of limited usefulness. Some of the temperatures ranging from about to 300 F.

methods, such as extraction with liquid sulfur A closed container may be u if The 30 dioxide, are limited in the degree of change of. time of treatment may range from a few minutes properties, and other methods, such as hydmup to several hours, depending to some extent genation, are limited in the direction in which up n the temperature employed, e alheuht 0f the change is effected. Hydrogenation, for exaluminum chloride used and the efliclen 0f i ample, is incapable of increasing the viscosity of agitation. The sludge formed in the process 35 the oil and is also incapable of-producinga lower is separated and t e ini g Sour oil is sweetviscosity index. For many applications a high ned a d Durifled,1lsua1ly y heetihg Wlth fuller's viscosity index is desired, but in some app1ica'- earth and lime, followed by filtration. The halo- I tions, such as the preparation of certain greases, ge a hydrocarbon ppe m h p very low viscosity indices are required. This inthe halogen content be eliminated in the form vention offers a flexible method by which any o the eerrespending yd e a e. property of a lubricating oil may be changed in The alteration in the P pe of e 0 ay either direction at will by selection of suitable p y be explained on the theory that a y conditions. thesis takes place, the hydrocarbon residue from In a copending application, Serial No. 598,096, t na d mpound niti with tam filed March 10,1932, we have described a method hydrocarbons found in the oil. While this is a of improving various hydrocarbon products by possible explanation it would be extremely dimtreating a mixture of inferior technical stocks, cult to substantiate such a theory in practice. or one of said stocks, at low temperatures with a To illustrate our process in more detail several I chlorine containing gas and,.eitherJsimultane-' illustrative examples will be given which repre- 5o ously' or subsequently,withsalurninumgchloride. sent practical embodiments of the invention.

T present, invention represents,- in some re- E'xample 1.One hundred volumes of a coastal spects, an improvement upon or an' extension of V lubricating distillate were agitated 1n 9, closed the pro'cessofthis prior application; container with 10 per cent by weight of aluminum t We have fouridthat, by treating various lubrichloride for two hours at a temperature of 5 F. and under a pressure of 100 pounds of ethyl chloride. After treatment, the sludge was permitted to settle and the sour oil was decanted. The latter wasthen steamed at 450 F. with 0.5 pound of fine Florida clay per gallon of oil and 0.6 pound of lime per acid number per barrel. After steaming the oil was filtered. The yield of finished oil was found to be volumes, showing the following comparative tests:

Charging Stock Product Gravity: A. P. I 20.7 23.7 Viscosity, S. U. V. 210 F 76 Viscosity index 17 54 Flash, 415 455 Fire, 0. CA F 495 525 Color, N. P. A 5.5 2.0 Carbon residue: Percent 0. 27 0.07

Charing stock Product Gravity: A. P. I 20.7 .2 Viscosiiy, S. U. V. 210 F 75 101 Viscosity index. 17 55 Flash, 0 C F 415 460 Fire, 0. C F- 495 530' Color, N. P. 5.5 2.75 Carbon residue: Percent 0.27 0.44

In this example the gravity, viscosity and viscosity index of the lubricating stock are raised by treatment with amyl chloride and aluminum chloride.

Example 3.-One-hundred volumes of the same coastal lubricating distillate as that used in Example 1 were agitated with 10 per cent of aluminum chloride and with 30 volumes of amylene dichloride for 2-hours at 175 F. The oil was finished in the same manner as in Example 1.

Ninety-eight volumes of finished oil were obtained showing the following comparative tests:

Charging stock Product Gravity: A. P. I 20.7 19.9 Viscosity, S. U. V 210 F 75 141 Viscosity index. 17 20 Flash, 0. 0.: 415 445 Fire, 0. 0.: F. 495 525 Color, N. P. A 5. 5 7 0 611. Carbon residue: Percent 0. 27 3 .27

This example illustrates a method of producing an extraordinary increase of viscosity with some increase in viscosity index, these changes being coupled with an increase in carbon residue.

Example 4.-One hundred volumes of mid-- continent bright stock were stirred with 10 per cent of'aluminum chloride and 50 volumes 'of amyl chloride for 2 hours at a temperature of 220 F. The oil was finished in the same manner as above. Eighty volumes of the fini hed oil were obtained showing the parative tests:

following com- Charging stock Product Gravity: A. P. I 23.0 27,9 Viscosity, S. U. V 210 F 151 94 Viscosity index- 73 98 Flash, 0. C: 545 500 Fire, 0. 0.: F--- 030 585 Pour: F +15 +20 Color, N. P. 7. 5 3. 75 Carbon residue: Percent 1. 75 0. 23

In this example the gravity of the oil is raised markedly, the viscosity index is increased and the carbon residue reduced.

Example 5.One hundred volumes of a low viscosity Pennsylvania type distillate were stirred with 5 per cent of aluminum chloride and with 50 volumes of amylene dichloride for 4 hours at a temperature of 175 F. The oil was finished as in Example 1. One hundred twelve volumes of finished oil were obtained showing thefollowing comparative tests:

Charging stock Product Gravity: A. P. I 28. 5 28.4 Viscosity, S. U. V. 210 58 73 Viscosity index-. 95 79 Flash, F-.. 440 465 Fire, 0. 0 F- 505 530 Color, N P A 2. 25 7.5

This example illustrates the possibility of increasing the viscosity of an oil without substan- 3 tial lowering of the A. P. I. gravity.

Example 6.-One hundred volumes of midcontinent bright stock were agitated with 2 per cent of aluminum chloride and 15 volumes of benzyl chloride for 1 hour at a temperature of 150 F. The oil was finished as above. Fiftyeight volumes of oil were obtained showing the following comparative tests:

Charging Stock Product Gravity: A. P. I 22. 8 20. 3 Viscosity, S. U. V. 210 F 156 122 Viscosity index Flash, 0. 0.: F 545 545 Fire, 0. C F. 605 610 Pour: +15 +20 Color, N. P. A. 4. 75 3. 25 Carbon residue: Percent 1. 42 0. 34

This table shows that a marked rise in A. P. I. gravity is produced by treatment with an aralkyl chloride. The carbon residue is lowered and the viscosity index is raised slightly.

Example 7.-One hundred volumes of midcontinent bright stock, the same as that used in Example 6, were stirred with 6 per cent of aluminum chloride and with 25 volumes of ortho dichlorobenzene for 2 hours at a temperature of F. The oil was finished as in Example 1. Seventy-six volumes of oil were obtained showing the following comparative tests:

Charging Stock Product Gravity: A. P. I 22.8 25.4 Viscosity, S. U V 210 F 156 152 Viscosity index- 85 88 lash, O. C 545 545 Fire, 0 C 005 525 Pour: F +15 +20 Color, N. P. A 4. 75 4. 25 Carbon residue: Percent 1. 42 0. 66

2,010,887 In this example the fire test was improved and the carbon residue lowered-with slight increases in gravity and viscosity index.

Example 8.-One hundred volumes of reduced Oklahoma crude were agitated in a closed container with 10 per cent of aluminum chloride and 10 per cent of chloroform for 2 hours at a temperature of 150 F. The sour oil was decanted from the aluminum chloride sludge and agitated with 5 per cent sulfuric acid for a time suflicient to decompose the suspended partiolesof aluminum chloride sludge. After settling out the dilute acid wash, the oil was contacted with fine clay and finally filtered through coarse burned clay. Ninety-nine volumes of oil were obtained showing the following comparative tests:

Charging stock Product Gravity: A. P. I 19.8 10.4 Viscosity, S. V. 210 F 138 159 Viscosity index 74 bel. 20

This example illustrates the possibility of markedly lowering the viscosity index and the A. P. I. gravity by the use of halogenated hydrocarbons having more than one halogen atom Chargi stock Product The above data illustrate the raising of theviscosity index and the A; P. I. gravity by treatment with halogenated aryl compounds.

While the above examples illustrate what we consider the best embodiments of our invention, various changes can be made without departing from the scope ofour invention. The above examples have been chosen to illustrate various types or classes of halogenated hydrocarbons which are applicable in our process. While in most cases only a single example of a group of compounds is given, our experiments indicate that substantially all members of the groups illustrated are equally operative. Typical members of alkyl, alkylene, aralkyl, and aryl halides are given to illustrate the action of these groups as a whole. Amongother halogenated hydrocarbons, suitable for raising the A. P. I. gravity and viscosity index .of lubricating oils, having low values of these constants, there may be mentioned the monochlorides of methane, propane, butanes, hexanes, 'etc., dichlorides of the ethylene dichloride series, and the products from the moderate chlorination of fractions of petroleum, including wax. It will be noted that all of these compounds have at least one halogen atom connected to a carbon atom, but not more than one chlorine is the only halogen illustrated in the examples, bromine substituted hydrocarbons are also applicable. In commercial operation, however, the cost of these compounds is usually pro.- hibitive.

Qn the other hand, if it is desired to lower the A. P. I. gravity and the viscosity index, use may be made of halogenated hydrocarbons having more. than onehalogen atom connected to a single carbon atom. As additional examples of such compounds there may be cited dichlorides of the ethylidene dichloride series, trichloretylene with its homologues, and the products of severe chlorination of fractions of petroleum. These examples illustrate other specific effects produced by typical halogenated hydrocarbons.

- As will be noted by studying the above examples, the results produced are not conditioned solely by the type of chlorinated hydrocarbon used, but also depend to some extent upon the temperature, pressure and the time employed during treatment, as well as upon the amounts oi aluminum chloride and chlorinated hydrocarbon used. with the aid of these examplesas a guide it is a rather simple matter to alter the characteristics of any given lubricating oil to meet specificationsof rather diverse character.

Various methods can be used for finishing or purifying the sour oil resulting from treatment with aluminum chloride and halogenated hydrocarbon. The above examples illustrate at least two suitable methods. A third method which may be mentioned is aslmple heating of the sour oil to temperatures at which the traces of suspended aluminum chloride sludge will completely react with the oil. This temperature is usually between 450 and 550 F. After the sludge is spent, the oil can be clarified by filtration.

The time of treatment required varies to some extent with the temperatures and pressures employed. At atmospheric pressures usually from 1 to 2 hours are required for treatment, while at pounds pressure and temperatures approaching 300 F., from 10 to 15 minutes is usually sufficient. In any case heating should be continued until reaction is complete.

In certain cases it has been found advantageous to fra'ctionate the all after treatment to separate out certain undesirable constituents. When' treating lubricating oils containing unsaturated or naphthenic lubricating fractions by our process, we sometimes secure lubricating oils that are mixtures of oils of improved quality with some fractions of inferior quality. A fraction, usually a high boiling fraction, is sometimes found in the treated oil having such characteristics as a low gravity, low viscosity index and a comparatively high carbon residue. Where such characteristics are not desired in the finished oil, a considerable improvement can u ally be obtained by distilling such a treated oil, any inferior fractions being discarded. In some cases the residuum obtained from such fractionation.

is found to have a quality superior to that of the distillate. In this case fractionation is of great advantage in producing a heavier oil of better grade.

Our invention may be illustrated with greater clarity by reference to the accompanying drawing, which shows, in the form of a fiow sheet, a typical process within the purview of our invention, wherein a lubricating oil stock is mixed with a halogenated hydrocarbon and the mixture is treated by a series of successive operations, with.

the ultimate production of a finished lubricating oil of improved properties. The several successive operations are indicated on the flow sheet by appropriate legends.

Referring to the flow sheet, a lubricating'oil stock is shown introduced into an agitator together with a halogenated hydrocarbon. Optionally, the halogenated hydrocarbon may be added under pressure. The halogenated hydrocarbon is of that type of. compound in which at least one halogen atom is-connected to a carbon atom, but not more than one halogen atom is connected to any one carbon atom.

Aluminum chloride is introduced into the agitator and the mixture agitated until the reaction is completed, after which the mixture is removed from the agitator to a sludge separator where the sludge is permitted to settle and is drawn ofi. As shown in the flow sheet, the remaining sour oil may be finished by one of several, alternative procedures.

it an acid finishing step is desirable, the sour oil from the sludge separator is introduced into an agitator and there agitated with weak sulfuric acid for a time sufificient to decompose the suspended particles of aluminum chloride sludge, after which the mixture is settled in-a sludge separator, the acid sludge drawn ofi and the remaining oil passed first through a fine clay and finally through a coarse clay filter. After filtration, the oil may be recovered as a finished lubrieating, oil. Optionally, however, it is desirable in some instances to fractionate the oil at this stage.

If, on'the other hand, it is desired to finish sour oil by a treatment diiferent from that just described, such sour oil may be introduced into a fire and steam still and heated to a temperature at which the traces of suspended aluminum chloride sludge completely react with the 011. At this stage, if desired, instead of a simple heating of the oil, the latter may be steamed at around 450 F. with'clay and lime. In either event, the halogenated hydrocarbon disappears at this stage, the halogen content being driven oil from the still and recovered in the form of the corresponding hydrogen halide. After either the simple heating or the treatment with clay and lime, the sweetened oil is filtered and recovered at this stage as a finished lubricating oil. In some instances the finished oil is fractionated in the v same manner as previously described.

The proportion of aluminum chloride used in our process can be varied widely. Usually from 1 to 10 percent by weight of thelubricating oil stock is found to be sufilcient. Use of larger proportions is usually attended with larger losses. A balance may usually be struck between the improvement desired in the oil, such as increase in viscosity, and the loss to sludge.

The'proportions of halogenated hydrocarbon .used in the process can likewise be varied widely.

' be noted from the above examples that amyl chloride and amylene dichloride give excellent results in increasing viscosity and viscosity index, as well as in producing high yields. We therefore consider these chlorides to be the most advantageous of the chlorinated hydrocarbons tested.

The simple admixture of light chlorinated hydrocarbons, such as ethyl chloride and amylene dichloride, for example, with lubricating oils produces a substantial reduction in viscosity. In contrast to this our process usually results in a lubricating oil of increased viscosity, even whensuch compounds are employed in quantities up to 50 per cent or more by weight. As mentioned, the chlorine is eliminated from the reaction mixture as hydrogen chloride. There is no yield of a light hydrocarbon corresponding to the chlorinated hydrocarbon employed. These facts indicate that our reaction is a synthesis, the residues of the halogenated hydrocarbons being combined with other residues during the reaction.

In many cases the operating procedure may.

be varied, within the scope of the following claims, to suit the particular material which is bein treated or the. particular product it is desired to produce. Some of these variations have been indicated above while others will be evident to those skilled in the art.

What we claim is:

1. In the treatment of lubricating oil, the process which comprises mixing a lubricating stock with a small percentage of aluminum chloride and with a low boiling halogenated hydrocarbon having not more than a single halogen atom attached to any one carbon atom, subjecting the mixture to a treatment substantially equivalent to that obtained by heating for from 1 to 2 hours at atmospheric pressure and at temperatures ranging from about 150 to 300 F., decanting the resulting sour oil, decomposing traces'of aluminum chloride sludge that remain in the sour oil by a method selected from a group consisting of, first, steaming the sour 'oil with a small amount of clay and with about 0.6 pound of lime per acidnumber per barrel, second, agitating with dilute sulfuric acid for a time sufficient to decompose suspended particles of sludge. separating the acid and contacting with clay, third, heating said sour oil to temperatures at which the traces of suspended sludge will completely react with the oil; then filtering the decomposed particles of sludge from the oil andrecovering a finished oil of increased viscosity index, low color N. P. A. and low carbon residue.

2. In the treatment of lubricating oil, the process which comprises mixing a lubricating stock with a small percentage of aluminum chloride and with a low boiling halogenated hydrocarbon having not more than a single halogen atom attached to any one carbon atom, subjecting the mixture to a treatment substantially equivalent to that obtained by heating for from 1 to 2 hours at atmospheric pressure and at temperatures ranging from about 150 to 300 F., decanting the resulting sour oil, decomposing traces of aluminum chloride sludge that remain in the sour oil by a method selected from a group consisting of, first, steaming the sour oil with a small amount of clay and with about 0.6 pound 'of lime per acid number per barrel, second, agitating with sulfuric acid having a concentration of about 5 per cent for a time suflicient to decompose suspended particles of sludge, separating the acid and contacting with clay, third, heating said sour oil totemperatures of about 450 to 550 for a time sufiicient to cause suspended sludge to completely react with the oil; then filtering the decomposed particles of sludge from the oil and recovering a finished oil of inviseolityindemloweolmltnLandlow earbonresidue.

3.1heprooessoiclahn1whereinthealuminum ehlorideisaddedinanamountequaltoirom 1 to 10 per cent by weight o i'the lubricating stock.

'4. The prooeu of claim 1 wherein the chloriisaddedinproportions equalingtromitoloopercmtbyweightoithelubristock. .Theprooessoiclaimi poduets obtained are fractionated to remove a portioninvinglowvaluesoigravityandviscosity 8.1!: the treatment of lubricating oil, the moons which comprises mixing a lubricating otoekwithasmallperoentageoialuminumchlowherein the reaction ride and with a low boiling. halogenatedhydroearbonhavingnotmorethanasinglehalogen attached to. any one carbon atom, subjectmixture to a treatment substantially I sour oil, steaming the amount of clay and with about .Gpmmdotlimeperacidnumberperbartreatment oi lubricating oil, the which comprises mixing a lubricating doekwithasnallpuoentage oi aluminum chlorldeanilwithalowboilimhalogenatedhydrocarbon having not more than a single halogen atom attached to any one carbon atom; subjectin themltturetoatrahncntmbstantiallyequivalenttothatobtainedbyheatingforfrom1to2 hursntatmoqiheriepreuireandat temperailfithebuikotthealmninmchloridesludge ing' the mixture to a treatment substantially equivalent to that obtained by heating for from 1 to 2 hours at atmospheric pressure and at temperatures ranging from about 150 to 300 F., separating the bulk of the aluminum chloride sludge from the resulting sour oil, heating said sour oil to temperatures at which the traces oi suspended sludge will completely react with the oil and filtering.

9. The process of claim 6 wherein the aluminum chloride is added in an amount equal to from about 1 to 10 per cent by weight of the lubricating stock and the chlorinated hydrocarbon is employed in quantities ranging from about 5 to 100 per cent by weight of said lubricating stock.

* 10. The process 01' claim 8 wherein they-aluminum chloride is added in an amount equal to from about 1 to 10 per cent by weight of the inbricating stock and the chlorinated hydrocarbon is employed in quantities ranging from about 5 to 100 per cent by weight of said lubricating stock.

11. The process of claim 6 wherein the chlorinated hydrocarbon is selected from a group consisting of amyi chloride andamvlenc dichloridcs.

. 12. The process of claim 8 wherein the chlori hated hydrocarbon is selected from a group consisting of amyl chloride and amylene dichiorizles.

EUGENE AYRES.

G. SMITH, 

